title: Radiotherapy for stage II and stage III breast cancer patients with negative lymph nodes after preoperative chemotherapy and mastectomy.
abstract: OBJECTIVE
  To evaluate the effect of postmastectomy radiotherapy (PMRT) in Stage II-III breast cancer patients with negative lymph nodes (pN0) after neoadjuvant chemotherapy (NAC).
  
  
  METHODS
  Of 1,054 breast cancer patients treated with NAC at our institution between 1990 and 2004, 134 had pN0 status after NAC and mastectomy. The demographic data, tumor characteristics, metastatic sites, and treatments were prospectively recorded. The effect of PMRT on locoregional recurrence-free survival and overall survival (OS) was evaluated by multivariate analysis, including known prognostic factors.
  
  
  RESULTS
  Of the 134 eligible patients, 78 (58.2%) received PMRT and 56 (41.8%) did not. At a median follow-up time of 91.4 months, the 5-year locoregional recurrence-free survival and OS rate was 96.2% and 88.3% with PMRT and 92.5% and 94.3% without PMRT, respectively (p = NS). The corresponding values at 10 years were 96.2% and 77.2% with PMRT and 86.8% and 87.7% without PMRT (p = NS). On multivariate analysis, PMRT had no effect on either locoregional recurrence-free survival (hazard ratio, 0.37; 95% confidence interval, 0.09-1.61; p = .18) or OS (hazard ratio, 2.06; 95% confidence interval, 0.71-6; p = .18). This remained true in the subgroups of patients with clinical Stage II or Stage III disease at diagnosis. A trend was seen toward poorer OS among patients who had not had a pathologic complete in-breast tumor response after NAC (hazard ratio, 6.65; 95% confidence interval, 0.82-54.12; p = .076).
  
  
  CONCLUSIONS
  The results from the present retrospective study showed no increase in the risk of distant metastasis, locoregional recurrence, or death when PMRT was omitted in breast cancer patients with pN0 status after NAC and mastectomy. Whether the omission of PMRT is acceptable for these patients should be addressed prospectively.
authors.affiliation: Department of Radiation Oncology, Institut Curie-Hôpital René Huguenin, Saint-Cloud, France. lescodan@crh1.org
authors.forename: Romuald
authors.initials: R
authors.lastname: Le Scodan
authors.forename: Jessica
authors.initials: J
authors.lastname: Selz
authors.forename: Denise
authors.initials: D
authors.lastname: Stevens
authors.forename: Marc A
authors.initials: MA
authors.lastname: Bollet
authors.forename: Brigitte
authors.initials: B
authors.lastname: de la Lande
authors.forename: Caroline
authors.initials: C
authors.lastname: Daveau
authors.forename: Florence
authors.initials: F
authors.lastname: Lerebours
authors.forename: Alain
authors.initials: A
authors.lastname: Labib
authors.forename: Sarah
authors.initials: S
authors.lastname: Bruant
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001365:Axilla; D001943:Breast Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D015413:Mastectomy, Simple; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011300:Preoperative Care / Q000379:methods; D012189:Retrospective Studies; D016896:Treatment Outcome